This invention relates generally to a flexible magnetic disk drive of the type used for writing in and reading out of a magnetic disk and more particularly to a flexible magnetic disk drive which is small and thin. In a conventional disk mechanism, a clamp is constructed of two components, namely, a coil spring and a clutch plate. Further, rotational power of the motor is transferred to a disk drive pulley directly by a belt. In such a construction of the prior art, design of a small and thin flexible magnetic disk drive is impeded by the mechanism of clamping of the disk, and it has not been possible to provide a mechanism for ejecting the disk in a small and thin flexible magnetic disk drive.
Recently, in the field of information equipment, the magnetic memory drive has been developing rapidly. In particular, a flexible magnetic disk drive is required to be small and thin because information equipment, such as, for example, a word processor, is in general use today and as a result, portable and compact equipment is desirable and required in many instances. The structure of a conventional flexible magnetic disk drive in accordance with the prior art is illustrated in FIG. 1 wherein the apparatus includes a front door A1, a lever A2 for lowering a clutch plate A3. Also included are a disk A4, a center pulley A5, a motor A6 and a belt A7. The clutch plate A3 is lowered by pushing the front door A1 so as to act on the lever A2 which is pivoted between its ends. The clutch plate A3 acts on the center of the disk A4 and clamps the disk against the center pulley A5 which is mounted on bearings for rotation. Rotation of the motor A6 is transferred to the pulley A5 by means of the belt A7. Thus, the disk A4 is rotatingly positioned relative to a magnetic read/write head A8 in the known manner.
The magnetic disk drive of FIG. 1 has disadvantages as follows when considering the design of a thin flexible magnetic disk drive. First, when operating the front door A1, a large force is required. When the vertical space is restricted, a clutch plate constructed using a coil spring A9 for determining the clamping pressure on the disk cannot be used. Also, when the providing a thin flexible magnetic drive, it is not easy to remove the disk from the drive. Thus, a mechanism for ejecting the disk is required in the drive but in actuality there is not enough space for such a mechanism.
Further, with reference to FIG. 1, when providing a mechanism for ejecting the disk, there is a possibility that the disk is ejected inadvertently by misoperation during the time period when writing in or reading of the disk is occurring. In such a misoperation the magnetic head A8 might be damaged. Also, if the door should be closed under a condition where the disk has not been pushed entirely into the opening, the disk is not clamped precisely at its center by the clutch mechanism and this damages the disk.
Further, relative to FIG. 1, when providing a thin drive, it is difficult to obtain sufficient space for the belt A7 which connects the motor A6 with the pulley for transferring the rotation of the motor. Also, where photoelectric elements for detecting whether write-in is possible or not are mounted to circuit substrates, it is difficult to position the photoelectric elements relative to each other. Additionally, in a construction where the frame upon which the components are mounted is formed by a stamping, there are the following disadvantages. Namely, when the apparatus components are fitted to the frame, the connecting portions of the frame are distorted and thereby the accuracy within the apparatus is not satisfactory. Additionally, when the structure is designed to be small, a solenoid for moving the magnetic head vertically cannot have the same structure as is conventionally used. Also, the solenoid is positioned close to the disk and a problem is caused that magnetic flux is lost.
The flexible magnetic disk drive in accordance with the invention eliminates the disadvantages described above and provides a thin flexible magnetic disk drive.
What is needed is a flexible magnetic disk drive which positively positions a magnetic disk in position for reading and writing, is small in size vertically and laterally, and includes a disk ejection mechanism.